McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Uncategorized topics .
| 401. |
During idling, mixture provided by simple carburetor is |
| A. | increasingly rich |
| B. | increasingly lean |
| C. | lean |
| D. | chemically correct |
| Answer» C. lean | |
| 402. |
The fuction of the choke is to provide |
| A. | lean mixture |
| B. | some mixture |
| C. | rich mixture |
| D. | stoichiometric mixture |
| Answer» C. rich mixture | |
| 403. |
Simple carburetor provides correct quality of mixture |
| A. | at all operating conditions |
| B. | during acceleration only |
| C. | during cruising only |
| D. | only at one throttle position |
| Answer» D. only at one throttle position | |
| 404. |
The correct expression for nozzle lip is |
| A. | tip height – fuel surface height |
| B. | tip height – throat height |
| C. | throat height – float chamber height |
| D. | fuel surface height |
| Answer» A. tip height – fuel surface height | |
| 405. |
The tip of the nozzle is kept |
| A. | at the same level as that of fuel in float chamber |
| B. | at level above the fuel level in float chamber |
| C. | at level below the fuel level in float chamber |
| D. | sometimes above, sometime below the fuel level in float chamber |
| Answer» B. at level above the fuel level in float chamber | |
| 406. |
The drawbacks of carburetor includes |
| A. | non uniform distribution in multi cylinder engines |
| B. | less breathing capacity |
| C. | slow response to change in operating conditions |
| D. | all of the above |
| Answer» D. all of the above | |
| 407. |
MPFI means |
| A. | metal point fuel injection |
| B. | multi point fuel injection |
| C. | metal power fuel injection |
| D. | multiple pin fuel injection |
| Answer» B. multi point fuel injection | |
| 408. |
In port injection system, location of injector is |
| A. | inside cylinder near intake port |
| B. | near carburetor |
| C. | inside intake manifold near intake port |
| D. | inside cylinder near exhaust port |
| Answer» C. inside intake manifold near intake port | |
| 409. |
In carburetor, choke is located on which side of the venturi? |
| A. | engine side |
| B. | air filter side |
| C. | at the venturi |
| D. | any where |
| Answer» B. air filter side | |
| 410. |
In carburetor, throttle valve is located on which side of the venturi? |
| A. | engine side |
| B. | air filter side |
| C. | at the venturi |
| D. | any where |
| Answer» A. engine side | |
| 411. |
In complete caruretor, idling passage opens in a draft tube at which position? |
| A. | engine side of throttle valve |
| B. | venturi side of throttle valve |
| C. | at the venturi |
| D. | none of the above |
| Answer» A. engine side of throttle valve | |
| 412. |
The cold start injector provides |
| A. | stoichiometric mixture |
| B. | rich mixture |
| C. | lean mixture |
| D. | heating of fuel |
| Answer» B. rich mixture | |
| 413. |
Ignition lag, spreading of flame and after burning are the stages observed during combustion in |
| A. | petrol engines |
| B. | diesel engines |
| C. | pi engines |
| D. | turbocharged engines |
| Answer» A. petrol engines | |
| 414. |
The combustion will not start immediately after spark because of |
| A. | flame propogation |
| B. | after burning |
| C. | ignition lag |
| D. | motoring |
| Answer» C. ignition lag | |
| 415. |
The time interval between formation of spark and appreciable pressure rise is |
| A. | spark advance |
| B. | ignition lag |
| C. | propogation lag |
| D. | burning lag |
| Answer» B. ignition lag | |
| 416. |
A motoring curve is plotted when |
| A. | when the vehicle is not running |
| B. | when engine is running at no load condition |
| C. | the cycle is taking place due to combustion of fuel |
| D. | the cycle is not fired |
| Answer» D. the cycle is not fired | |
| 417. |
Which of the following is not necessary condition for starting of combustion process in SI engines? |
| A. | compression of charge |
| B. | presence of fuel |
| C. | presence of oxygen |
| D. | formation of spark |
| Answer» A. compression of charge | |
| 418. |
Effect of spark in SI engines is____ |
| A. | ionisation of gases |
| B. | rise in volume |
| C. | rise in pressure |
| D. | rise in temperature |
| Answer» D. rise in temperature | |
| 419. |
In SI enginesmaximum amount of fuel is burnt during the stage____ |
| A. | pre-burning |
| B. | ignition lag |
| C. | flame propagation |
| D. | after burning |
| Answer» C. flame propagation | |
| 420. |
In SI engines the flame travels in____ |
| A. | spherical shape |
| B. | circular shape |
| C. | linear direction |
| D. | sinusoidal pattern |
| Answer» A. spherical shape | |
| 421. |
In D-MPFI system the quantity sensed is ____ |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | mixture flow rate |
| Answer» A. pressure | |
| 422. |
The D-MPFI system responds to vacuum sensed in____ |
| A. | carburettor |
| B. | intake manifold |
| C. | exhaust manifold |
| D. | piston |
| Answer» B. intake manifold | |
| 423. |
L-MPFI ststem responds to____ |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | flow rate |
| Answer» D. flow rate | |
| 424. |
Arrange the phases of combustion in ascending order according to amount heat evolved in each phase |
| A. | ignition lag, after burning, flame propagation |
| B. | ignition lag, flame propagation, after burning |
| C. | after burning, flame propagation, ignition lag |
| D. | after burning, ignition lag, flame propagation |
| Answer» A. ignition lag, after burning, flame propagation | |
| 425. |
In SI engines flame speed decreases with increase in |
| A. | intake temperature |
| B. | peak temperature |
| C. | compression ratio |
| D. | residual gases |
| Answer» D. residual gases | |
| 426. |
In SI engines, Maximum flame speed is obtained when equivalance ratio is___ |
| A. | less than 1 |
| B. | between 1 to 1.1 |
| C. | between 1.1 to 1.2 |
| D. | greater than 1.2 |
| Answer» C. between 1.1 to 1.2 | |
| 427. |
With increase in compression ratio, flame travels |
| A. | faster |
| B. | slower |
| C. | with same speed |
| D. | with fluctuations |
| Answer» A. faster | |
| 428. |
In SI engines flame speed always increases with____ |
| A. | turbulence |
| B. | air-fuel ratio |
| C. | residual gases |
| D. | compression ratio |
| Answer» D. compression ratio | |
| 429. |
With increase in speed, the crank angle required for flame propagation___ |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | cant predict |
| Answer» C. remains same | |
| 430. |
If cooling water temperature is decreased flame speed___ |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | cant predict |
| Answer» B. decreases | |
| 431. |
Increasing cooling water temperature in SI engines, kncocking tendency_____ |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | cant predict |
| Answer» A. increases | |
| 432. |
To reduce knocking, the fuel in SI engine should have ____ self ignition temperature |
| A. | low |
| B. | high |
| C. | any |
| D. | automatic |
| Answer» A. low | |
| 433. |
Detonation in SI engine means |
| A. | sudden ignition of charge before delay period is over |
| B. | pre-ignition of charge before the spark |
| C. | auto-ignition of charge before the spark |
| D. | auto-ignition of charge after the delay period is over |
| Answer» D. auto-ignition of charge after the delay period is over | |
| 434. |
Knocking in SI engine occurs when___ |
| A. | flame reaches the unburnt charge before delay period is over |
| B. | flame reaches after the delay period is over |
| C. | spark is produced before charge coming in |
| D. | spark is produced several times |
| Answer» B. flame reaches after the delay period is over | |
| 435. |
Pre-ignition takes place when____ |
| A. | flame reaches the unburnt charge before delay period is over |
| B. | ignition takes place after spark |
| C. | ignition starts before spark |
| D. | flame travels very fast |
| Answer» C. ignition starts before spark | |
| 436. |
Larger combustion chambers |
| A. | increase detonation |
| B. | decrease detonation |
| C. | do not affect detonation |
| D. | cant say |
| Answer» A. increase detonation | |
| 437. |
To prevent knocking flame propagation should be |
| A. | retareded |
| B. | accelerated |
| C. | sinusoidal |
| D. | upfront |
| Answer» A. retareded | |
| 438. |
To reduce knocking in SI engines, self ignition temperature of fuel should be ____ |
| A. | high |
| B. | low |
| C. | varying |
| D. | constant |
| Answer» A. high | |
| 439. |
Which of the following is not an effect of increased intake temperature? |
| A. | less delay period |
| B. | higher flame speed |
| C. | more knocking tendency |
| D. | does not affect anything |
| Answer» D. does not affect anything | |
| 440. |
As load increases, the knocking tendency of SI engines____ |
| A. | increases |
| B. | decreases |
| C. | cant predict |
| D. | remains same |
| Answer» A. increases | |
| 441. |
As the speed of flame travel increases, detonation___ |
| A. | increases |
| B. | decreases |
| C. | cant predict |
| D. | remains same |
| Answer» B. decreases | |
| 442. |
AS distance of flame travel increases, detonation |
| A. | increases |
| B. | decreases |
| C. | cant predict |
| D. | remains same |
| Answer» A. increases | |
| 443. |
Detonation tendency is maximum for air:fuel ratio___ |
| A. | 8:1 to 10:1 |
| B. | 10:1 to 12:1 |
| C. | 12:1 to 14;1 |
| D. | 16:1 to 18:1 |
| Answer» C. 12:1 to 14;1 | |
| 444. |
To reduce detonation, the spark plugh should be located |
| A. | near to intake valve |
| B. | at the corner |
| C. | centrally |
| D. | neat piston |
| Answer» C. centrally | |
| 445. |
Which is not a probable location of preignition? |
| A. | spark plugh tip |
| B. | exhaust valve |
| C. | remote corner of chamber |
| D. | intake valve |
| Answer» D. intake valve | |
| 446. |
Knocking in SI engines will be less if |
| A. | delay period is less and flame speed is high. |
| B. | delay period is less and flame speed is less |
| C. | delay period is high and flame speed is high |
| D. | delay period is high and flame speed is less |
| Answer» C. delay period is high and flame speed is high | |
| 447. |
In SI engines, to aviod knock, combustion chamber should have___ |
| A. | small bore |
| B. | large bore |
| C. | large flame path |
| D. | large ratio of flame path to bore |
| Answer» A. small bore | |
| 448. |
Octane rating is___ |
| A. | measure of fuel resistance to knock in ci engines |
| B. | measure of fuel assistance to knock in si engines |
| C. | measure of fuel assistance to knock in ci engines |
| D. | measure of fuel resistance to knock in si engines |
| Answer» D. measure of fuel resistance to knock in si engines | |
| 449. |
For octane rating a standard reference fuel consists of |
| A. | iso-octane only |
| B. | n-heptane only |
| C. | combination of 2,2,4 trimethyl pentane and n-heptane |
| D. | combination of iso heptane and n-octane |
| Answer» C. combination of 2,2,4 trimethyl pentane and n-heptane | |
| 450. |
2,2,4 trimethyl pentane has octane number equal to |
| A. | 1 |
| B. | 0 |
| C. | 100 |
| D. | 120 |
| Answer» C. 100 | |
Done Studing? Take A Test.
Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.